Baker&#39;s oven



March 20, 1928.

C. B. coMsTocK BAKER S OVEN Filed Sept. 5. 1923 5 Sheets-Sheet Corr v360711.; $06K @Hoznuqs March 20, 1928.

C- B. COMSTOCK BAKERS OVEN Filed Sept. 5. 1923 5 Sheets-Sheet '2gwue'nfoz Co 72713. C'a m .r (0c A.

March 20, 1928.

c. B. COMSTOCK BAKERS OVEN Filed Sept. 5. 1923 5 Sheets-Sheet 5 gnuanfozC0 7")", .3 Cmmrtoc A.

March 20, 1928.

v 1,663,115 C. B; COMSTOCK BAKERS OVEN Filed Sept. 5. 1923 5Sheets-Sheet 4 Corr 3. C'Omnfoc/f March 20, 1928. 1,663,115

, v C. B. COMSTOCK BAKERS OVEN Filed Sept. 5. 1923 5 Sheets-Sheet 5Patented Mar. 20, 1928. i v i i v UNITED STATES PATIENT OFFICE.

CORRY'B. COMSTOCK, OF NEW YORK, N. Y., ASSIGNOR TO COMSTOGK OVENCOMPANY,

1110., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

BAKER/S ovEN.

Application filed September 5, 1923. Serial No. 661,064.

The present invention relates to improvement of the invention is 'shown,although ments in ovens, and will be shown in connecthese drawings aremerely illustrative and tion with bakers ovens. The object of the in nosense restrictive of the invention. invention is to provide a novelconstruction In the drawings and arrangement of parts constituting suchFig. 1 is a plan of an oven embodying the 60 an' oven, and an improvedmethod of operatpresent invention. J ing the same, whereby theefliciency of the Fig. 2 is a side elevation; oven will be materiallyincreased and an Fig. 3 is a longitudinal vertical section, on improvedproduct obtain d, an enlarged scale, of portions of the oven.

v The invention is particularly adapted for Fig. 4 is an elevationof thedelivery end 05 use with ovens of the type employingan of the oven.endless conveyor for transporting the prod- Fi 5 is a sectional view,substantially on ucts, for example, bread, through the oven, the line5'-5 of Figure 1, on an enlarged and one ot the objects of the inventionis to scale.

provide an oven of this type which will be Fig. 6 is an enlarged view,partly in-seccomposed of a series of similar sections tion, of one ofthe-heat exchangers. which may be readily assembled to that an Fig. 7 isan elevation of one of'the burners oven of'any desired length may beinitially detached, partly inhorizontal section. built or' the length ofthe oven increased or Fig. 8 is an elevational detail of a part of 20decreased, if desired. the b rner. p v Q In the useof ovens of-the typereferred to, Fig. 9 1s an elevation, partly in section, of

particularly in baking, the vapor rising from One t e f l mixers.

Fig. 10..is a section on the line 10-10 of the products during thebaking operation, and any vapor caused by the introduction of 1g- 5steam or moisture to the baking chamber, Fig. 11 1s a section on theline '1111 of collects in the upper part of the baking Fig- 6. achamber, and as this vapor collects, the pres- Fig. 12 is a section, onan enlarged scale, sure thereof tends to.carry it toward thesubstantially on the line 12-12 of Figure 7. open ends of the oventhrough which the -F g- 13 1s adetail perspective view of a I 30 endlesscarrier enters and leaves the baking short pilot light and means forsupplying s5 chamber. It is customary. to provide fans g h Iet 0-adjacent the open ends of the baking cham- Fig. 14 1s a sectional viewshowing a porber by which such vapor may be withdrawn. 131011 of h b n rand the Short pilot light.

The vapor accumulating in the upper por- Referring to the drawings, themproved 35 tion of the oven necessarily exerts pressure e n f rmed of aseries of sections, each on the productsbeing baked, and, to some includng outer and inner side walls 1, 2, and degree, retards the expansiveaction or rising an. intermediate body 3 of suitable heat insuof theloaf under the action of the. baking l ting materia The. walls 1, 2, arepreferheat. ably formed of sheet metal plates suitably One of theparticular objects of the inven- Strengthened by angle iron uprights 4,5,

tion is to provide means whereby the prodi h m y Serve as meanseonneetmg t b i b k d ill b li d'f ad o1n1ngsect1ons so that a bakingchamber cessive pressure of suchvapor, so that the ff any desired lengthmay be readily pro loaf may freely expand to the maximum dee ThesectlQns ulllts m y be O y gree and a-lighter' product be obtained thandes red length, suitably aligned and secured is possible ith th th d d bth to give a continuous oven of the desired pro-' ortions.

means heretofore employed. The baking chamber has a metalbottom 6 Afurther object of the invention is to uti- I lize the heatedvaporwithdrawn from the nd top 7 supported by suitable an is bar 0baking chamber as a means for h i g from the inner-sideplates 2, and t eheat -1 0 the gaseous fuel which is upplied to the insulating body 3extends ove the ,plfi e oven burners. 7 and beneath the bottom plate 6so t, at the The invention will be hereinafter de-. entire chamber issurrounded by such mate- 55 scribed in detail in connection with theacrial.

companying drawings, in which one embodi- I The endless conveyorlbywhich the articles 10:

to be baked are carried through the baking chamber is supported byrollers or wheels traveling on trackv members 8 within the Y panyingdrawings, is more or less conventional, the invention not beingrestricted to any particular form of conveyor, for ex ample.

The conveyor 9 extends throughout the "length of the baking chamber, andmay project, and is here so shown, from the ends of said chamber. At itsreceiving end the conveyor is supported on sprockets 13 carried by ashaft 10 extending transversely across the end of the oven, 3, the ovencasing and the body of heat insulating material is extended beneath andabout the sides and in front of the conveyor supporting sprockets, sothat, when constructed. with the ends of the conveyor projecting, theseparts are encased, except for a relatively small space which is providedto receive the products to be transported into the baking chamber. Asshown, the'casing and insulating body extend a considerable distanceabove the axis of the shaft 10 and practically to the horizontal planeofthe upper run of the conveyor.

'vided through which The supporting shaft 11 and sprockets for thedelivery end of the conveyor, beyond the end of the baking chamber, aresimilarly protected, a suitable opening 12 being prothe baked productsmay. be removed from the conveyor by an separate train of attendant. Thesprockets 13, which supports the. delivery end of the conveyor, arecarried by independent shafts separately the frame structure of theoven, and on each of said shafts is secured a gear 14, 14'. With saidgearsmesh pinions 15, 15', on a shaft 16 that extends transverselyacross the delivery end of the oven, and on which are secured two gears17, 17. The gears 17, 17', are driven by pinions 18, 18, on a shaft 19,which is also provided with a worm wheel 20 that is driven by a wormshaft 21 actuated by a suitable motor 22 that is shown as supported.

on the top of the oven. By providing a sprocket 13, 13, the spacerequired for the gear trains is reduced to a minimum, and the conveyor 9is positively and uniformly driven. It will be seen that the severalpinions and gears are arrangedin close, lateral, proximity, and projectbut a limited distance laterally from the oven, so that there is noundue waste of floor space in installing an oven constructed inaccordance with the invention.

A conduit 25 (see Figs 1 and 5) is pro-.

and, as shown in Figure tending tubes 32, supp insulating material 3. A

gearing for driving each vided beneath the bottom of the oven cham-"her, which conduit extends throughout the length of the chamber and isprovided,'at suitable intervals in its top wall, with inlet aperturesadapted to be controlled by dampers 26, the handles 27 of which extendthrough a side wall of the oven. About midway the length of the oven theconduit communicates with the lower member ofa flue or conduit 28,which, as here shown, extends upward along one side of the oven, betweenthe walls 1, 2, thereof, and inward over the top plate 7, andcommunicates with a conduit 29 having two branches, which communicate,respectively, with the casings of two heat exchangers 30, 1, by whichfuel (preferably gaseous) employed for heating the oven is preliminarilyheated. I

The two heat exchangers are of similar construction, each comprising acasing having therein a series of longitudinally exers, andcommunicating, at their ends, with chambers formed in the heads 33, 34.Each of said casings is provided with an outlet with which connects onemember of a suction pipe 36', that, in turn, communicates with thecasing of a suction: fan 37, driven by a suitable motor 38.1-A stack 39,connected to the fan casing, is provided for carrying away the heatedair and vapor withdrawn by the fan from the baking chamber through theconduits 25, 28, 29, and the spaces within the casings 30,31, about theseries of tubes therein.

At one end each casing 30,31, is connected with a suitable pressure pump40, actuated by a motor 41, and the said pumps are, respectively,connected by pipes 41' with two mains 42, 43, which-may, as here shown,extend longitudinally along one side of the oven, being embedded inthebody of heat gas supply pipe 44 is connected to the inlet end of thecasing 30, while the casing 31 is provided, at its correspondingend,with an air inlet.

By the action of the pumps 40, gas and air, under pressure, are suppliedto the mains 42, 43, respectively,

'45 with mixers 46.

orted by suitable head- Jon lUC)

Various forms of mixers may be provided,

1 .but the one illustrated comprises a casing,

having, at one end, an external thread 47 to receive a couplingconnecting it withf'the branch supply pipe 45, and having screwed intoits opposite end a coupling 48, which connects with burners. Within thecasing 46 of the mixerare arranged a series of mixing plates-:46.connected together by a bolt or rod extend at its ends to braces 46 theinterior of the casing. The said plates are slightly concave in crosssection, and

pipes 49 leading tothe several 'ing longitudinally of the casing andsecured extending across have their peripheries slitted to provide aseries of separated blades which are slightly bent orbowed, so thatportions thereof projeict beyond the plane of the body of the p ate.

The several plates are so related that the currents ofair and gaspassing through the casing 46 are thoroughly intermingled.

.ings, only a single group ;of .burners is Preferably the burners (seeFigs. 2 and 5) are divided into several groups, each group beingconnected with one of the mixing chambers- To avoid confusion in thedrawshown, but it will be understood that .as

many similar groups as may be necessary are provided, and each may beconnected with an individual or independent mixer 46.

, tures 55, 56, in the side wall plates 1, 2, said apertures beingarranged in'two vertically separated series, the upper series being in aplane above the upper run of the conveyor 9, and the lower series ofapertures 56, being in a plane between the two runs of the con- 1 veyor.

The burners extend substantially across the baking chamber (see Fig. 5),and each is of U form, the one leg of the burner being connected to thecombustible fuel supply pipe, and, the other end being closed,preferably, as shown, by a removable plug. The two parallel sectionsofthe burner are in substantially the same horizontal plane, and each isprovided with a series of perforations 61, at which the combustible fuelis ignited.

' Preferably these apertures or burner openings 61 are only providedinthe portions of the:tubes which face toward the ends of the bakingchamber. The supply of combustible fuel to each burner is independentlycontrolled by a valve 62.

To facilitate removal. of the burners from the baking chamber, each,preferably, consists of three sections, namely, end sections 63, 64, andan intermediate, bowed section 65. The several sections are eonnected inany suitable manner, as by sleeve members 66, 67, which are provided.with lugs 68 connected by suitable bolts 69. A slot' 67 is formed inthe" sleeve ,67 in alignment with the burner openings 61; By thisconstruction, it is possible, iwhen the burner is disconnected from.thegsupp1yfmain, to move it laterally through the openings 55, 56,

until the bolts 69 are accessible, when the sections of the burner canbe readily'discon nected, and separately withdrawn.- This substantiallyU-shaped burner is advanta-- geous for the reason that it will give auniform temperature throughout the width of the baking chamber. Theaverage of the two temperatures of the flame adjacent the U or returnbend will be the same as the average temperatures at the inlet end andthe blank end of the burner, and this is a distinct advantage .over astraight burner, in which there is variation in temperature from theinlet end to the blank end.

To ensure ignition of the gas issuing from the openings 61 in the burnermember, which are remote from the supply pipe a small tube 70 isprovided, Such tube leads from the burner section 63 to a point near theinner end of the opposite stra' ht member of the burner, and a'pilotlight i maintained at its free end. Thiswill serve to ensure ignition ofthe combustible gas issuing from the adjacent straight member of theburner in case the same should be extinguished from any cause, as, forexample, by a reduction of pressure in the burner by reason of the ad-.

jacent section of the baking chamber becoming so hot as to actuate thethermostatically controlled valve 50, before referred to.

Between the upper section of the com veyor 9 and the upper series ofburners. is arranged 'a' plate 80, which extends substantiallythroughout the length of the baking chamber and is connected with-theside plates thereof at suitable intervals, so that spaces 81 areprovided through which the heat of the burners'may pass downwardly andhave free access to the articles on the upper run of the conveyor. Thislate or shield 80, over the top of the baking chamber, effectivelyseparates the generated vapors from the products under treatment fromthe flame of the burners, and serves to confine the vapors'about andabove the material being baked or treated. Furthermore, the shield 80tends to confine the heat and ensures a uniform temperature throughoutthe entire area in which the material, such as loaves of bread, is beingtreated. The conveyors commonly used in ovens of the charare soconstructed that they provide a practically continuous plate, on whlchthe receptacles for the bread, for example, are supported. This providesa substantially continuous Wall extending above the lower series ofburners 60. which will transm t heat therefrom to the articles on thecon veyor. As noted above, the plate 80 acts to preacter to which thepresent invention relates vent the vapor, generated by the action of yheatv on the moist dough, from directly passinginto contact with theupper set of burners where it would have a tendency to smother theflame; and also serves to maintain a body of such vapor about thearticles on the conveyor. 1

The vapor produced during the baking 0 eration contains a considerablepercentage of alcohol, the action of which on the loaf .to aconsiderable degree determines the color of the crust and imparts adesirable flavor to the body of the loaf. Bythe construction describedloaves of bread, for example, are enveloped in a saturated vapor duringthe baking operation which results in giving the desired color to thebaked loaf. If the shield or baflie 80 is not employed and the pressureof the generated vapor on the loaves reduced by drawing the vapordownward bethe baking operation.

The operation of the several parts of the embodiment of the inventionillustrated have been briefly referred to in the foregoing. description,and will be clear to those skilled in the art. Y

It will be seen thatby the arrangement described and illustrated anyvapor generated during the baking operation is directly withdrawndownward into the duct 25, so

that the articles being baked are entirely relieved from any pressuretherefrom. The

heated vapor and air thus withdrawnfrom the baking chamber 1S caused totraverse the casings of the heat exchangers 30, 31,

each of said casings being preferably provided with, baffles 30, whichcause said air and vapor to pursue'acircuitous course in travelingthrough the casings, thus imparting a maximum amount of heat to the airor gas passing through the tubes 32. The pumps or blowers 40 maintain auniform pressure upon the air and gas supplied to the mains whichcommunicate with the several mixers, and as thef'supply of gas to eachgroup ofburners, as well as that to each individual burner of a groupcan be easily controlled, the temperature of the baking chamber may bemaintained at any desired degree.

By practically enclosing the projecting end sections of the conveyorwith a body of heat insulating material, undersirable cooling, andconsequent loss of heat, by exposure of such end sections is avoided.

To enable the attendants toreadilyv inspect the interior .of the bakingchamber,

suitable inspection windows 90 are provided at various points in thewalls of the oven.

It will be seen that the construction of scribed, the pilot lig the ovenframe is such that any desired number of units or sections may bereadily assembled to provide a baking chamber of the required length,and the gearing employed for driving the conveyor is arranged in a verycompact manner closely adjacent the sides of the oven, so that a minimumamount of floor space is required.

If, for any reason, the openings in the side walls of the oven must beclosed, this may be readily done by means of removable blocks ofsuitable material.

Each burner may have a relatively short pilot light section 90 extendinginto it from a header 91 on the outside of the oven, said pilot lightsection extending, for example, as a far as the first opening 61. Withsuch arrangement, any burner may be extinguished without affecting saidpilot sections, and quickly ignite from such pilot when the flow of fuelis resumed.

Besides serving to maintain proper oombustion at the outlets of eachburner to which gas is being supplied, the pilot lights are effective inpreventing undesirable cooling of the oven during between bakingperiods.

the intervals of time I Bakers ovens are ordinarily not operatedcontinuously and during the inactive periods 'it is desirable to cut offor materially reduce the supply of gas to the burners, to avoidunnecessary consumption of gas and reduce the expense of operation andalso to prevent the temperature in the baking chamber from becomingexcessive;

By such an arrangement as herein dets may be operative for indefiniteperiods of time and when at the termination of a baking period thesupply of gas to the burners is .cut oil, by manipulation ofthe valves51- or 62, the heat derived from the pilot lights will be sufficient toprevent material reduction of the vtemperature in the baking chamber.This avoids the delay commonly incident to restoringthe desired bakingtemperature at v the beginning of a succeeding baking period,

before introducing articles to be baked into the oven.

Thepilotlights will, of course, operate to relight the burners followinga resump its travel through the oven chamber, and, of

course, the action of the suction fan may be varied or discontinued tosu t different condltlons. I.

.tion of the flow of gas thereto, after such By preheating the gas andair prior to its delivery to the burners,.the volume is increased, andit is possible to make the ori- 1,ees,1 15

chamber, a substantially horizontalsupport for articles to be bakedwithin the chamber, means for heating the chamber including burnersarranged above said support, a stationary horizontal bafile positionedbetween the article support and the burners above such support, andadapted ,to maintain a body of vapor generated in the baking operationin contact with the articles bein baked while shielding said burnersfrom suc vapor, and means for relieving the articles being baked fromexcessive pressure of said vapor.

2. In a bakers oven, the combination of a chamber, a substantiallyhorizontal support for articles to be baked within the chamber, meansfor heating the chamber including burners arranged above said support, astationary bafliearranged between said support and burners and adaptedto maintain a body of vapor generated in the baking operation in contactwith the articles being baked while shielding said burners from saidvapor, and means for relieving the articles being baked from excessivepressure of said vapor by creating a suction downward through thechamber.

downward through the baking chamberwhile a body of such vapor ofsubstantially uniform character and pressure ismaintained on thearticles throughout the length:

of the chamber. r

5. In a bakers oven, the combinationof, a baking chamber, gaseous fuelburners for heating said chamber, means for relieving the articles beingbaked of excessive pressure of vapor gener' bed in the baking chamber,

and means for causing the vapor withdrawn from the chamber topreliminarily heat all of the gaseous fuel for the burners.

6. In a bakers oven, the combination of a baking chamber, means forheating said chamber, means for supporting within the chamber articlesto be baked, means for maintaining above and in contact with thearticles'being baked a body of vapor generated from said articles by thebaklng operation, -a conduit communicating with the interior of thechamber below the horizontal .plane of the said supporting means, andgeneratedmeans for withdrawing vapor from the articles being bakeddownward aboutthe articles and through said conduit, whereby all of thearticles being baked in the chamber are subjected to a vapor ofsubstantially uniform character and pressure.

7 In a bakers oven, the combination o:f a baking chamber, means forheating sald.

chamber, a conduit extending longitudinally of and below the bottom ofthe chamber and communicating with the chamber at a plurality of points,and means for creating suetion through the conduit to withdraw heatedair and vapor from the chamber.

8. In a bakers oven, the combination of a. i

bakin chamber, gaseous fuel burners within said 0 amber, means forsupplying a combustible gaseous mixture under pressure to the burners,means for preliminarily heating the elements of said mixture includin aheat exchanger on top of the oven, an means for conducting heated airand vapor from the oven chamber to said heat exchanger.

9. In a bakers oven,.the combination of a baking chamber, gaseous'fuelburners within said chamber, means for supplying fuel under pressure tothe burners, and means for withdrawing heated air and vapor from thechamberv and utilizing it to preliminarily heat the gaseous fuel.

10.;In a bakers oven, the combination of a baking chamber, a luralit'yof gaseous fuel burners or heating t 1e baking chamber, mains forail-and gas respectively, a mixer associated with each roup of bumersand connected to both sai ma1ns, means for supplying air and gas to saidmams, re.- speetively under pressure, and means for withdrawing heatedair. and vapor from the oven chamber and using'it to heat the air andgas before entering saidimains.

11. In a bakers oven the combination of a baking chamber, an endlesscarrier extending longitudinallythrough said chamj ber, burners withinthe chamber above and.

below the upper member of the endl ss carrier, means for supplying fueltothe burn- 4 plying therein.

baking chamber having a conduit extending longitudinally of the bottomthereof and provided with a plurality of inlets communicatin with thechamber, an outlet be-. ing providbd in the top of the oven, atransverse conduit connecting the longitudinal conduit with said outlet,a suction'fan connected with the outlet, gaseous fuel burners forheating the oven chamber, and means for preliminarily heating the gassupplied to the burners including a heat exchanger arranged in theconnection between saidoutlet and suction fan.

13. In a bakers oven, the combination of a baking chamber, gaseous fuelburners for heating said chamber, two casings each'provided with aseries of longitudinally extend-- 14. In a baker s oven,- thecombination of a baking chamber, a conduit extending longitudinally ofthe bottom of said chamber and communicating therewith, an endlessconyeyor travelling longitudinally ofthe baklngachamber, burners withinthe chamber above and below the upper section of the etween the upperserles of burners and the conveyor, anda.

conveyor, a baflie plate suction fan arranged outside the oven andconnectedto said conduit, for the purpose described.

15. In a bakers oven, the combination of "a baking chamber, means forsupportinga series of articles to be baked within and moving themthrough the baking chamber,

a burner, within the baking chamber above the path of the articles to bebaked through' the chamber, means arranged'beneath the burner and aboveand out of contact with the articles being baked, adapted to maintaina'body of vapor, generated from the articles being baked,. in contactwith the upper surfaces of said articles and to prevent such vaporpassing directlyintocontact with the burner, and means for causing saidvapor -to pass downward through the baking chamher to relieve thearticles .being baked from excessive pressure by said vapor;- I

16. In a bakers oven, the combination of abaking chamber, means forsupportinga series of articles to be baked within and moving themthrough the baking chamber, burners, within the baking chamber above andbelow the pathv of the articles to be baked, and a battle arran edbetween the up- .per burner and the artic es being baked and provided atits sides with flanges that extend downward into the baking chamberadjacent the side walls thereof.

17. In a bakers oven the combination of a baking chamber, means forsupporting a series of articles to be baked within and fiioving'themthrough the baking chamber, burners within the baking chamber above andbelow the path of the articles to be baked through the chamber, meansfor pre venting vapor generated during the baking operation from passingdirectly upward in-' to contact with the burner above the articles beingbaked, and means for causing said vapors to move downward through thebaking chamber.

18. In a bakers oven, the combination of a baking chamber, means forsupporting a series of articles to be baked within. and moving themthrough the baking chamber, burners within the baking chamber above andbelow the path of the articles to be baked through the chamber, meansfor causing preventing it from passing directly upward into contact withthe upper burner. I

19. In a bakers oven, the combination with a baking chamber, of a seriesof U- shape burners arranged within the chamber with the parallelmembers of each substantially horizontal, and one of said membersextending through a side wall of the chamber.

20. In a bakers oven, the combination with a baking chamber, of a seriesof U- shaped burners arranged within the chamber with the parallelmembers of each substantially horizontal, and one of said membersextending through a side wall of the chamber, the parallel members ofeach burner comprising two, detachably connected sections.

21. In a bakers oven, the combination with a baking chamber, of a seriesof U- shape burners arranged within the chamber with the parallelmembers of each substan- 'tially horizontal, and one of said membersextending through a side wall of the chamber, and a small tube extendingfrom the member that passes through the oven wall, adjacent said wall,to a point adjacent the other member and the bowed section between saidmembers.

22."In a bakers oven, the combination with a baking chamber, of a seriesof burners within the baking chamber each consisting of a U-shape tubeclosed at one end and provided with lateral perforations along the outerfaces of its substantially arallel members, the 'unclosed one of w ichextends through a side wall of the chamber.

23. In a bakers oven, the combination with a baking chamber, of a seriesof horizontal burners extending laterally into the chamber from a sidewall, each burner comprising two sectional, parallel laterallyperforated members, one of which extendsthrough the chamber wall and theother of which is closed at one end, and an intermediate curved section,and means outside the transversely of the baking chamber and ar-- rangedin groups which are spaced apart longitudinally of the chamber toprovide a plurality of heating zones, and a thermostatically actuatedvalve controlling each group of burners.

25. In a bakers oven, the combination of a substantially horizontal,elongated, baking chamber, means for moving articles to be bakedlongitudinally through the baking chamber, a plurality of burnersextending transversely of the baking chamber and spaced apartlongitudinally of the chamber to provi e a plurality of heating zones,manually actuated means controlling each burner, and supplemental burnercontrol means adapted to be automatically actuated by variations in thetemperature of the zone of thebaking chamber in which each burner isarranged.

26. In a bakers oven, the combination of a baking chamber, means formoving articles to be baked through the baking chamber, a plurality ofburners for heating the baking chamber, a pilot light adjacent eachburner, and manually operable valves controlling the supply of fuel tothe several burners without affecting the supply of fuel to-the pilotlights.

27. In a bakers oven, the combination of a substantially horizontal,elongated, baking chamber, means for moving articles to be bakedlongitudinally through the baking chamber, a plurality of burnersextending transversely of the baking chamber and spaced apartlongitudinally of the chamber to provide a plurality of heating zones, a

pilot light adjacent each burner, a thermostatically [actuated valvecontrolling supply of fuel to all ofthe burners of each heating zone,and an'independent manually operable valve controlling the su ply offuelto each individual burner, the pi ot lights being supplied withfuelindependent of said valves.

In testimonyfwhereof I have hereunto set my hand.

ooaRY B. COMS'IIOCK;

